Device for clamping and guiding crocheting needles for a crocheting machine

ABSTRACT

A device for clamping and guiding crocheting needles for a crocheting machine. On the one hand a clamping device for the crocheting needles and on the other hand a knock-over comb are to be created, which permit a very fine spacing. To this end, in the bottom part (27) and in the clamping cover (29) of a clamping device (12), opposite, straight needle beds (73, 74) are arranged closely together. The needle beds (73, 74) have wall surfaces that are inclined in a V-shape. A knock-over comb (20, 80) fixed to the machine has upwardly projecting teeth (86) for the crocheting needles. The spacing of the needle beds and guide elements is at least 12, in particular 14 per centimeter of machine width. The holding bar (23) fixed to the machine and the bottom part (27) of the clamping device (12) have recesses, in particular chambers (77, 76) that face one another, which permit the clamping device to move too close to the teeth (86).

The invention relates to a device for clamping and guiding crochetingneedles, in particular latch type needles, lace needles, and thecrocheting needles which the experts call "patent needles". The devicemust be such that it can be used on crocheting machines in general, inparticular on crochet galloon machines. From the EP-PS 0 110 271(BERGER) a device is known for the clamping of crocheting needles,which, however, does not co-operate with a known knock-over comb, butwith a knock-over bar with an upper free, straight edge. On the otherhand, a special construction of the bottom part and clamping cover of aclamping device for crocheting needles is known from the EP-PS 0 244 656(BERGER). There the needle shanks are placed in rectangular grooves ofthe bottom part and clamping cover, between which rectangular websremain.

By the present invention, on the one hand a clamping device for thecrocheting needles, and on the other hand a knock-over comb are to becreated, which permit a very fine spacing, i.e. at least 12, inparticular 14, however, also further needles per cm of machine width. Ithas proved inexpedient to mill in grooves with a rectangularcross-section in this great fineness. A problem in this connection wasthe obtaining of the necessary precision. On the other hand it provedinexpedient to work with a knock-over bar with a straight upper edge. Itwas, on the contrary, necessary to guide the needle shanks to preventthat associated eye needles guide the warp threads around the wrong oraround two crocheting needle heads each. In addition, measures wererequired to ensure that also with the high required fineness, thedistances between the lengthwise threads of a to be crocheted band orthe like are accurately maintained during the mesh formation.

By the invention according to claim 1, this object can be achieved by aclever combination of various measures, only some of which are alreadyknown. Surprisingly, bands, in particular elastic bands, can becrocheted with same, the lengthwise threads of which are positioned atidentical distances from one another, also in the case of a spacing ofin particular 14 per cm of machine width, so that a very uniform lookingband can be produced.

Furthermore, the problems of the clamping and guiding of the crochetingneedles are solved in a perfect manner. What proved important for thehigh precision when producing the grooves of the clamping device and theprecise clamping-in of the needle shanks, was the V-shaped arrangementof the wall surfaces of the grooves (needle beds).

Another important aspect lies in creating a possibility to guide theclamping device to very close to the teeth of the needle comb, so thatthe mounting of the crocheting needles inside the clamping device alsoacts on that part of the crocheting needles which during operationprojects beyond the teeth.

Further developments of the invention can be noted from the sub-claims.

The accuracy of the distances between the lengthwise threads of thecrocheted bands can be positively influenced by the proper choice of theclamping-in length of the crocheting needles. If during the knock-overoperation the heads of the crocheting needles can be retracted so farthat they, for example, only still project by 2 mm, no irregularity ofthe crocheted band can be perceived.

The parts of the knock-over comb provided with teeth can be accommodatedin a groove open to the top of a holding bar, as a result of which ahigh precision of the distances between the teeth can be obtained.

The knock-over comb can, in principle, be constructed in two differentways, i.e. on the one hand with blocks that are arranged closelytogether, each of which has an upwardly pointing tooth, and on the otherhand with plates which at the top have teeth with wall surfaces that areinclined towards one another in the shape of a V.

The grooves produced in this way have in particular triangular shape,but may have rectangular or any inbetween shapes. All that is importantis that the needle shanks can be inserted from the top and are held atthe sides.

Finally, the shanks of the crocheting needles may have cross-sectionalshapes other than the usual ones. The shanks may have a sharp narrowedge at both the top and bottom, or they may have a rounded narrow edge.

Exemplified embodiments with further features of the invention aredescribed in the following with reference to the drawings, wherein:

FIGS. 1 and 2 show in a side view a set of crocheting tools of a gallooncrocheting machine in two extreme operating positions.

FIG. 3 is a perpendicular partial cross-section in the plane IV--IV ofFIG. 2 through the clamping device illustrated there and the clamped-inchrocheting needles.

FIG. 4 shows in a side view from the right one of the knock-over combsillustrated in FIG. 2, but without crocheting needles.

FIG. 5 shows in the same view as FIG. 4 a knock-over comb withtriangular teeth.

FIG. 6 is a cross-section through the knock-over comb according to FIG.5.

FIGS. 7 and 8 are cross-sections through two different embodiments ofcrocheting needles.

FIGS. 1 and 2 show an arrangement of crocheting tools similar to that ofFIG. 1 of the European Patent Specification 110 271 (BERGER). In FIGS. 1and 2 one notes one of several crocheting needles 10 clamped into aclamping device 12, with a shank 10a and a head 10b, as well as an eyeneedle 2 of a group of eye needles arranged next to one another on aneye needle bar 3, which serve to feed in the warp threads 4. A threadcomb 6 serves to feed in a group of elastic threads 8. Weft threadguides 14 and 15, which are moved transversely to the drawing plane,serve to feed in weft threads 17 and 18. The elastic band 22 produced bymesh formation is drawn off downwards in the direction of the arrow 26.

This arrangement can be used, among others, to produce elastic bandswith crocheted lace.

A clamping device 12, illustrated at the left in FIGS. 1 and 2, for theshanks 10a of the crocheting needles is fastened in the known manner toa needle bar 25 and can be moved together with same to the left andright. FIG. 2 shows the left end position, FIG. 1 the right one. Theclamping device 12 has a clamping cover 29 and a bottom part 27, whichmust be pressed together with the aid of screw bolts 19 to clamp in thecrocheting needles.

FIG. 3 is a partial cross-section of the clamping device in a planeVI--VI in FIG. 2. In the clamping cover 29 and bottom part 27, V-shapedgrooves 73 and 74, respectively, with slanting wall surfaces 78 aremilled in, positioned closely together and lying exactly opposite oneanother. The grooves extend over the entire width of the clamping coverand bottom part that can be seen in FIG. 2, and all have the same shapeand width. In FIG. 3 only some of the grooves are shown. The group ofgrooves must be imagined continued to the right.

In FIG. 3 on the right a group of shanks 10a1 of crocheting needles isshown, which both at the top and the bottom have a sharp edge 89 (FIG.8) (preferred shape). On the left in FIG. 3 single shanks 10a1 and 10a2are shown with a different cross-sectional shape, i.e. a rectangularshape (10a2) or in shape of rounded top and bottom edges (10a1). Alwaysneedles of only one cross-sectional shape are used.

In the case of a 14 spacing, every unit E in FIG. 3 consisting of needleand associated inbetween space amounts to 0.71 mm. So that the warpthreads 4 and the elastic threads 8 as well as their knots can be passedthrough between adjoinint crocheting needles, inbetween spaces of 0.33mm are required. This leaves a width of 0.38 mm for the crochetingneedles.

For a 15-spacing and even finer spacings a corresponding arrangementapplies.

To obtain coarser spacings than shown in FIG. 3 on the right, theneedles can be inserted in only every second, third, fourth, etc. pairof grooves.

The arrangement with triangular grooves on the one hand makes itpossible to mill in the grooves very closely together, which is requiredfor the desired fine spacing, and on the other hand to take outindividual needles after loosening the screw connection of the clampingdevice and to replace them by new ones, during which operation the otherneedles remain unchanged in their former position.

As shown in FIG. 1 and 2, clamping cover 29 and bottom part 27 arepressed together by screw bolts 19. By not illustrated, but known means,it is ensured that the clamping cover 29 cannot move in the horizontaldirection (right-left in FIG. 3) relative to the bottom part 27, so thata skew position of the needle shanks is securely avoided.

FIGS. 1 and 2 show a main cross-bar 21 fixed to the machine, to which aknock-over comb 20 is fastened. The knock-over comb comprises aplate-like holding bar 23, which extends in the direction of the machinewidth and stands perpendicularly. As illustrated in FIG. 1 and 2, agroove 23a is milled into the holding bar from the top. FIG. 4 shows acut-out of the knock-over comb 20. Blocks 70 are placed closely togetherin the groove, each of which blocks 70 has in the centre an upwardlyprojecting tooth 70a. Open grooves 71 with a rectangular cross-sectionbetween every two teeth each serve to guide to guide the shank 10a andhead 10b of a crocheting needle 10. The blocks 70 are first of all justplaced in the groove closely together, and are only subsequentlyfastened by glueing. This serves to ensure that the blocks lie closelytogether and that very accurate distances are maintained between theteeth 70a. This construction is suitable for very fine spacings (up to a16-spacing), where a high precision of the distances between the grooves71 is important for the guiding of the needles.

In FIG. 1 and 2, to the right of the knock-over comb 20, a hold-back baris arranged in such a way that between the two there remains space fordrawing off the finished crocheted elastic bands 22.

When using very thin crocheting needles 10 it is important that theclamping device 12 can be guided as closely as possible to the teeth 70aof the knock-over comb 20, so that the part of the crocheting needlesprojecting from the clamping device becomes as short as possible. Topermit this, the holding bar 23 of the one side and the bottom part 27of the clamping device of the other side have recesses, e.g. chamfers 77and 76, respectively, that fit together. As shown in FIG. 1, in this waythe clamping device can be guided to close to the teeth 70a.

Matching this, the clamping-in length of the crocheting needle shanks ischosen in such a way that the heads 10b of the crocheting needles can beretracted to the left so far that they only still project by about 2 mmfrom the guide spaces between the teeth 70a (FIG. 2). In this positionthe formed meshes are knocked over. Due to the fact that thefree-standing needle parts are guided very precisely, the use of verythin crocheting needles of 0.38 mm width and less becomes possible. Onthe other hand, the distances between the needle heads during theknocking over are maintained very accurately. In this way a good lookingband is obtained, with which the distances between the elastic threads 8show no visible differences.

FIG. 5 and 6 show another embodiment of a knock-over comb 80. Parts thatare identical to those in FIG. 1 and 2 have been given the samereference numerals, e.g. the holding bar 23 with a groove 23a produced,for example, by milling. Thin plates 82 are inserted next to one anotherin this groove and fastened by glueing. Every plate is provided at thetop with triangular teeth 86 (with slanting wall surfaces 85) of thesame size and shape as the teeth which according to FIG. 3 resultbetween the needle beds 73 and 74. Every plate 82 has a greaterhorizontal length than shown in FIG. 5, so that a group of needles thatco-operate for the crocheting of a band can be guided together by onesingle plate.

Matching this triangular shape of the teeth and grooves, needles can beused, the shanks 10a1 of which have a sharp edge 89 at the top as wellat the bottom, as illustrated in FIG. 8.

The plates 82, the same as the blocks 70 with teeth 70a according toFIG. 4, are made, for example, of brass. Also copper, bronze or asuitable plastic can be used, so that there will be as little frictionas possible between the grooves 84 and 71, respectively, and the steelcrocheting needles 10.

The distance between the height of the crocheting needles 10 and thegrooves 71 and 84, respectively, according to FIG. 4, 5, and 6, isadjusted in such a way that during operation the bottom edges of theneedles move freely to and fro inside the grooves. The distances betweenthe teeth 70a (FIG. 4) are greater than the thickness of the crochetingneedles. As a result of these two measures the crocheting needles willonly now and then touch the walls of the grooves 71, 84, in which case acorrection is required. In this way the friction is reduced to aminimum.

The needle beds 73 and 74 (FIG. 3) and the grooves 84 (FIG. 5) need notnecessarily have a triangular shape, i.e. they need not have a pointedbottom 83, and the teeth 86 according to FIG. 5 and correspondinglyaccording to FIG. 3 also need not end in sharp edges 81. As shown inFIG. 7, the bottoms of the grooves 84a may be rounded surfaces 83a, andthe teeth 86a may end in rounded surfaces 81a. This also appliescorrespondingly to the bottom part 27 and the clamping cover 29according to FIGS. 1 and 2. When using plates 82 with grooves 84aaccording to FIG. 7, the needle shanks 10a3 may have correspondingrounded edges 90 (FIG. 9).

The described constructions can be adapted analogously to other types ofcrocheting devices.

    ______________________________________                                        LIST OF REFERENCE NUMERALS                                                    ______________________________________                                         2           Eye needle                                                        3           Eye needle bar                                                    4           Warp thread                                                       6           Thread comb                                                       8           Elastic threads                                                  10           Crocheting needle                                                10a          Shank                                                            10a1, 10a2   Shank                                                            10a3         Shank                                                            10b          Head                                                             12           Clamping device                                                  14, 15       Weft thread guide                                                17, 18       Weft thread                                                      20           Knock-over comb                                                  21           Main cross-bar, fixed to the machine                             22           Elastic bands                                                    23           Holding bar                                                      23a          Groove                                                           24           Hold-back bar                                                    25           Needle bar                                                       26           Arrow                                                            27           Bottom part of the clamping device                               29           Clamping cover                                                   70           Blocks                                                           70a          Tooth                                                            71           Groove                                                           73, 74       Needle bed                                                       76, 77       Chamfer                                                          78           Wall surface                                                     80           Knock-over comb                                                  81           Sharp edge                                                       81a          Rounded surface                                                  82, 82a      Plate                                                            83           Pointed groove bottom                                            83a          Rounded surface                                                  84, 84a      Groove                                                           85           Wall surface                                                     86, 86a      Tooth                                                            89, 90       Edge                                                             E            Unit                                                             ______________________________________                                    

We claim:
 1. Device for clamping and guiding crocheting needles havingshanks, for a crocheting machine,a) wherein in a bottom part (27) and ina clamping cover (29) of a clamping device (12) for the shanks (10a) ofthe crocheting needles (10), opposite, straight needle beds (73, 74)which needle beds are arranged closely together, b) and wherein thespacing of the needle beds and guide elements is at least 12 percentimeter of machine width, characterized in that c) the two oppositeneedle beds (73, 74) for the crocheting needles have wall surfaces (78)that are inclined towards one another in a V-shape, d) a knock-over comb(20, 80) fixed to the machine has upwardly projecting teeth (86) forguiding the needles, e) the teeth (86) have wall surfaces (85) whichform grooves in a V-shape, f) a holding bar (23) fixed to the machineand the bottom part (27) of the clamping device (12) have recesses thatface one another, permitting the clamping device to move in closerelationship to the teeth (86).
 2. Device according to claim 1,characterized in that the knock-over comb (23, 80) has a groove (23a),open to a top portion thereof, for accommodating plates (82) providedwith the teeth (86).
 3. Device according to claim 1, characterized inthat the wall surfaces (85) of the teeth (86) form sharp edges andgroove bottoms (83).
 4. Device according to claim 1, characterized inthat the parts provided with teeth are made of a material which causeslittle friction with the steel of the crocheting needles.
 5. Deviceaccording to claim 1, characterized in that the wall surfaces at theedges are interconnected by means of rounded surfaces (81a, 83a). 6.Device according to claim 1, characterized in that the shanks (10a1) ofthe crocheting needles have sharp opposite edges (89).
 7. Deviceaccording to claim 1, characterized in that the shanks (10a2) of thecrocheting needles have rounded opposite edges (90).